TPageControl 上有多个 TWebBrowser 时, 如何协调 Back、Forward - 回复 "飘逸的蓝" 的问题

问题来源: http://www.cnblogs.com/del/archive/2007/12/13/993840.html#1804933

---

代码:

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ExtCtrls, OleCtrls, SHDocVw, ComCtrls;



type

  TForm1 = class(TForm)

    Panel1: TPanel;

    Edit1: TEdit;

    Button1: TButton;

    Button2: TButton;

    Button3: TButton;

    PageControl1: TPageControl;

    procedure CommandStateChange(ASender: TObject; Command: Integer; Enable: WordBool);

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure Button3Click(Sender: TObject);

    procedure FormCreate(Sender: TObject);

    procedure PageControl1Changing(Sender: TObject; var AllowChange: Boolean);

    procedure PageControl1Change(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  TabSheetArr  : array[0..2] of TTabSheet;

  WebBrowserArr: array[0..2] of TWebBrowser;

  BoolArr      : array[0..2] of record B,F: Boolean end;

  WebActive: TWebBrowser;



procedure TForm1.FormCreate(Sender: TObject);

var

  i: Integer;

begin

  Button1.Caption := 'Go';

  Button1.Default := True;

  Button2.Caption := 'Back';

  Button3.Caption := 'Forward';

  Button2.Enabled := False;

  Button3.Enabled := False;

  Edit1.Text := 'http://del.cnblogs.com';



  for i := 0 to Length(TabSheetArr) - 1 do

  begin

    TabSheetArr[i] := TTabSheet.Create(PageControl1);

    TabSheetArr[i].PageControl := PageControl1;

    TabSheetArr[i].Caption := 'TabSheet' + IntToStr(i+1);

    WebBrowserArr[i] := TWebBrowser.Create(TabSheetArr[i]);

    TWinControl(WebBrowserArr[i]).Parent := TabSheetArr[i];

    WebBrowserArr[i].Align := alClient;

  end;

  PageControl1.ActivePageIndex := 0;

  WebActive := WebBrowserArr[0];

  WebActive.Navigate(Edit1.Text);

  WebActive.OnCommandStateChange := CommandStateChange;

end;



procedure TForm1.PageControl1Changing(Sender: TObject;

  var AllowChange: Boolean);

var

  i: Integer;

begin

  i := PageControl1.ActivePageIndex;

  BoolArr[i].B := Button2.Enabled;

  BoolArr[i].F := Button3.Enabled;

end;



procedure TForm1.PageControl1Change(Sender: TObject);

var

  i: Integer;

begin

  i := PageControl1.ActivePageIndex;

  WebActive := WebBrowserArr[i];

  Edit1.Text := WebActive.LocationURL;

  WebActive.OnCommandStateChange := CommandStateChange;

  Button2.Enabled := BoolArr[i].B;

  Button3.Enabled := BoolArr[i].F;

end;



procedure TForm1.Button1Click(Sender: TObject);

begin

  WebActive.Navigate(Edit1.Text);

end;



procedure TForm1.Button2Click(Sender: TObject);

begin

  WebActive.GoBack;

end;



procedure TForm1.Button3Click(Sender: TObject);

begin

  WebActive.GoForward;

end;



procedure TForm1.CommandStateChange(ASender: TObject; Command: Integer; Enable: WordBool);

begin

  case Command of

    CSC_NAVIGATEBACK   : Button2.Enabled := Enable;

    CSC_NAVIGATEFORWARD: Button3.Enabled := Enable;

  end;

end;



end.


 
   

窗体:

---

object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 388

  ClientWidth = 737

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  OnCreate = FormCreate

  PixelsPerInch = 96

  TextHeight = 13

  object Panel1: TPanel

    Left = 0

    Top = 0

    Width = 737

    Height = 30

    Align = alTop

    Caption = 'Panel1'

    TabOrder = 0

    DesignSize = (

      737

      30)

    object Edit1: TEdit

      Left = 8

      Top = 5

      Width = 425

      Height = 21

      TabOrder = 0

      Text = 'Edit1'

    end

    object Button1: TButton

      Left = 439

      Top = 2

      Width = 66

      Height = 25

      Caption = 'Button1'

      TabOrder = 1

      OnClick = Button1Click

    end

    object Button2: TButton

      Left = 574

      Top = 2

      Width = 75

      Height = 25

      Anchors = [akTop, akRight]

      Caption = 'Button2'

      TabOrder = 2

      OnClick = Button2Click

    end

    object Button3: TButton

      Left = 655

      Top = 2

      Width = 75

      Height = 25

      Anchors = [akTop, akRight]

      Caption = 'Button3'

      TabOrder = 3

      OnClick = Button3Click

    end

  end

  object PageControl1: TPageControl

    Left = 0

    Top = 30

    Width = 737

    Height = 358

    Align = alClient

    TabOrder = 1

    OnChange = PageControl1Change

    OnChanging = PageControl1Changing

  end

end


 
   

把上面的例子全部改成动态建立的方法(在之前的窗体上多加一个 Button4 用于添加页面):

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ExtCtrls, OleCtrls, SHDocVw, ComCtrls;



type

  TForm1 = class(TForm)

    Panel1: TPanel;

    Edit1: TEdit;

    Button1: TButton;

    Button2: TButton;

    Button3: TButton;

    PageControl1: TPageControl;

    Button4: TButton;

    procedure CommandStateChange(ASender: TObject; Command: Integer; Enable: WordBool);

    procedure Button3Click(Sender: TObject);

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure FormCreate(Sender: TObject);

    procedure PageControl1Changing(Sender: TObject; var AllowChange: Boolean);

    procedure PageControl1Change(Sender: TObject);

    procedure Button4Click(Sender: TObject);

  private

    procedure GetBackForwardBool;

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  TabSheetArr  : array of TTabSheet;

  WebBrowserArr: array of TWebBrowser;

  BoolArr      : array of record B,F: Boolean end;

  WebActive: TWebBrowser;



procedure TForm1.FormCreate(Sender: TObject);

var

  i: Integer;

begin

  Button1.Caption := 'Go';

  Button1.Default := True;

  Button2.Caption := 'Back';

  Button3.Caption := 'Forward';

  Button2.Enabled := False;

  Button3.Enabled := False;



  Button4.Caption := 'AddPage';

  Button4.Click;

  WebActive := WebBrowserArr[0];

  WebActive.OnCommandStateChange := CommandStateChange;

end;



procedure TForm1.GetBackForwardBool;

begin

  BoolArr[PageControl1.ActivePageIndex].B := Button2.Enabled;

  BoolArr[PageControl1.ActivePageIndex].F := Button3.Enabled;

end;



procedure TForm1.PageControl1Changing(Sender: TObject; var AllowChange: Boolean);

begin

  GetBackForwardBool;

end;



procedure TForm1.PageControl1Change(Sender: TObject);

var

  i: Integer;

begin

  i := PageControl1.ActivePageIndex;

  WebActive := WebBrowserArr[i];

  Edit1.Text := WebActive.LocationURL;

  WebActive.OnCommandStateChange := CommandStateChange;

  Button2.Enabled := BoolArr[i].B;

  Button3.Enabled := BoolArr[i].F;

end;



procedure TForm1.Button1Click(Sender: TObject);

begin

  WebActive.Navigate(Edit1.Text);

end;



procedure TForm1.Button2Click(Sender: TObject);

begin

  WebActive.GoBack;

end;



procedure TForm1.Button3Click(Sender: TObject);

begin

  WebActive.GoForward;

end;



procedure TForm1.Button4Click(Sender: TObject);

var

  n: Integer;

begin

  n := Length(TabSheetArr);

  if n > 0 then GetBackForwardBool;

  SetLength(TabSheetArr, n+1);

  SetLength(WebBrowserArr, n+1);

  SetLength(BoolArr, n+1);



  TabSheetArr[n] := TTabSheet.Create(PageControl1);

  TabSheetArr[n].PageControl := PageControl1;

  TabSheetArr[n].Caption := 'TabSheet' + IntToStr(n+1);

  WebBrowserArr[n] := TWebBrowser.Create(TabSheetArr[n]);

  TWinControl(WebBrowserArr[n]).Parent := TabSheetArr[n];

  WebBrowserArr[n].Align := alClient;

  PageControl1.ActivePageIndex := n;

  PageControl1.OnChange(PageControl1);

end;



procedure TForm1.CommandStateChange(ASender: TObject; Command: Integer; Enable: WordBool);

begin

  case Command of

    CSC_NAVIGATEBACK   : Button2.Enabled := Enable;

    CSC_NAVIGATEFORWARD: Button3.Enabled := Enable;

  end;

end;



end.